How Emerging Markets Can Get Their Mojo Back

Over the past five years, developing economies have been responsible for over two-thirds of global economic growth. Over the past decade, the share of developed-country exports bought by their developing partners has increased to almost 50% from 25%. In recent years China alone has consumed about half the world's cement, iron ore, steel, coal and lead, lifting commodity prices.

But the tide of growth has started to recede. The International Monetary Fund just cut its emerging-market growth forecast by over a full...